Light therapy for preventing seasonal affective disorder

Barbara Nussbaumer; Angela Kaminski‐Hartenthaler; Catherine A Forneris; Laura C Morgan; Jeffrey H Sonis; Bradley N Gaynes; Amy Greenblatt; Jörg Wipplinger; Linda J Lux; Dietmar Winkler; Megan G Van Noord; Julia Hofmann; Gerald Gartlehner

doi:10.1002/14651858.CD011269.pub2

Lichttherapie zur Vorbeugung von saisonal abhängiger Depression

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Referencias

References to studies included in this review

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estudios excluidos
otras referencias

Meesters Y, Beersma DG, Bouhuys AL, van den Hoofdakker RH. Prophylactic treatment of seasonal affective disorder (SAD) by using light visors: bright white or infrared light?. Biological Psychiatry 1999;46:239‐46.

References to studies excluded from this review

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estudios incluidos
otras referencias

Graw P, Gisin B, Wirz‐Justice A. Follow‐up study of seasonal affective disorder in Switzerland. Psychopathology 1997;30:208‐14.

Kasper S, Rogers SL, Yancey AL, Schulz PM, Skwerer RG, Rosenthal NE. Phototherapy in subsyndromal seasonal affective disorder (S‐SAD) and "diagnosed" controls. Pharmacopsychiatry 1988;21:428‐9.

Kjellman B, Lindwall/Sundel K, Stain/Malmgren R. The effect of prophylactic light therapy in SAD. Society Light Treatment Biological Rhythms 1997;9:24.

Google Scholar

Lafer B, Sachs GS, Labbate LA, Thibault A, Rosenbaum JF. Phototherapy for seasonal affective disorder: a blind comparison of three different schedules. American Journal of Psychiatry 1994;151:1081‐3.

Meesters Y, Lambers PA, Jansen JH, Bouhuys AL, Beersma DG, van den Hoofdakker RH. Can winter depression be prevented by light treatment?. Journal of Affective Disorders 1991;23:75‐9.

Meesters Y, Jansen JH, Beersma DG, Bouhuys AL, van den Hoofdakker RH. Early light treatment can prevent an emerging winter depression from developing into a full‐blown depression. Journal of Affective Disorders 1993;29:41‐7.

Meesters Y, Jansen JH, Beersma DG, Bouhuys AL, van den Hoofdakker RH. An attempt to prevent winter depression by light exposure at the end of September. Biological Psychiatry 1994;35:284‐6.

Meesters Y, Jansen JH, Beersma DG, Bouhuys AL, van den Hoofdakker RH. Light therapy for seasonal affective disorder. The effects of timing. British Journal of Psychiatry 1995;166:607‐12.

Most Els IS, Scheltens P, Van Someren Eus JW. Prevention of depression and sleep disturbances in elderly with memory‐problems by activation of the biological clock with light ‐ a randomized clinical trial. Trials 2010;11:11‐9.

Norden MJ, Avery DH. Dawn simulation for subsyndromal winter depression. American Psychiatric Association. Abstracts. Paper No. 109A2000.

Google Scholar

Partonen T, Lonnqvist J. The influence of comorbid disorders and of continuation light treatment on remission and recurrence in winter depression. Psychopathology 1995;28:256‐62.

Partonen T, Lonnqvist J. Prevention of winter seasonal affective disorder by bright‐light treatment. Psychological Medicine 1996;26:1075‐80.

Rohan KJ. Cognitive behavioral approaches to seasonal depression [NCT00076245]. ClinicalTrials.gov [www.clinicaltrials.gov]2004.

Google Scholar

Rohan KJ, Roecklein KA, Tierney Lindsey K, Johnson LG, Lippy RD, Lacy TJ, et al. A randomized controlled trial of cognitive‐behavioral therapy, light therapy, and their combination for seasonal affective disorder. Journal of Consulting & Clinical Psychology 2007;75:489‐500.

Rohan KJ, Roecklein KA, Lacy TJ, Vacek PM. Winter depression recurrence one year after cognitive‐behavioral therapy, light therapy, or combination treatment. Behavioral Therapy 2009;40:225‐38.

Rohan KJ, Evans M, Mahon JN, Sitnikov L, Ho S, Nillni YI, et al. Cognitive‐behavioral therapy vs. light therapy for preventing winter depression recurrence: study protocol for a randomized controlled trial. Trials [electronic resource] 2013;14:82.

Terman JS, Terman M, Amira L. One‐week light treatment of winter depression near its onset: the time course of relapse. Depression and Anxiety 1994;2:20‐31.

Google Scholar

Thorell LH, Kjellman B, Arned M, Lindwall‐Sundel K, Walinder J, Wetterberg L. Light treatment of seasonal affective disorder in combination with citalopram or placebo with 1‐year follow‐up. International Clinical Psychopharmacology 1999;14 Suppl 2:S7‐11.

University of Vermont, National Institute of Mental Health. Cognitive‐Behavioral Therapy vs. Light Therapy for Preventing SAD Recurrence. clinicaltrials.gov2014.

GlaxoSmithKline. A 7‐Month, Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Comparison of 150‐300mg/day of Extended‐Release Bupropion Hydrochloride (WELLBUTRIN XL) and Placebo for the Prevention of Seasonal Affective Disorder in Subjects with a History of Seasonal Affective Disorder Followed by an 8‐Week Observational Follow‐up Phase. GSK ‐ Clinical Study Register [www.gsk‐clinicalstudyregister.com]2003.

Google Scholar

Modell JG, Rosenthal NE, Harriett AE, Krishen A, Asgharian A, Foster VJ, et al. Seasonal affective disorder and its prevention by anticipatory treatment with bupropion XL. Biological Psychiatry 2005;58:658‐67.

GlaxoSmithKline. A 7‐Month, Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Comparison of 150‐300mg/day of Extended‐Release Bupropion Hydrochloride (WELLBUTRIN XL) and Placebo for the Prevention of Seasonal Affective Disorder in Subjects with a History of Seasonal Affective Disorder Followed by an 8‐Week Observational Follow‐up Study. GSK ‐ Clinical Study Register [www.gsk‐clinicalstudyregister.com]2004.

Google Scholar

Modell JG, Rosenthal NE, Harriett AE, Krishen A, Asgharian A, Foster VJ, et al. Seasonal affective disorder and its prevention by anticipatory treatment with bupropion XL. Biological Psychiatry 2005;58:658‐67.

GlaxoSmithKline. A 7‐Month, Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Comparison of 150‐300mg/day of Extended‐Release Bupropion Hydrochloride (WELLBUTRIN XL) and Placebo for the Prevention of Seasonal Affective Disorder in Subjects with a History of Seasonal Affective Disorder Followed by an 8‐Week Observational Follow‐up Phase. GSK ‐ Clinical Study Register [www.gsk‐clinicalstudyregister.com]2003.

Google Scholar

Modell JG, Rosenthal NE, Harriett AE, Krishen A, Asgharian A, Foster VJ, et al. Seasonal affective disorder and its prevention by anticipatory treatment with bupropion XL. Biological Psychiatry 2005;58:658‐67.

Wirz‐Justice A, Graw P, Krauchi K, Gisin B, Arendt J, Aldhous M, et al. Morning or night‐time melatonin is ineffective in seasonal affective disorder. Journal of Psychiatric Research 1990;24:129‐37.

Additional references

Ir a:

estudios incluidos
estudios excluidos

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd Edition. Washington, DC: American Psychiatric Association, 1980.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 3rd Edition. Washington, DC: American Psychiatric Association, 1987.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th Edition. Washington, DC: American Psychiatric Association, 2000.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th Edition. Washington, DC: American Psychiatric Association, 2013.

Begg CB, Mazumdar M. Operating characteristics of a rank correlation test for publication bias. Biometrics 1994;50:1088‐101.

Berg TJ1, Spekreijse H. Near infrared light absorption in the human eye media. Vision Research 1997;37:249‐53.

Byrne B, Brainard GC. Seasonal affective disorder and light therapy. Sleep Medicine Clinics 2008;3(2):307‐15.

Ciarleglio CM, Resuehr HES, McMahon DG. Interactions of the serotonin and circadian systems: nature and nurture in rhythms and blues. Neuroscience 2011;197:8‐16.

Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta‐analysis detected by a simple graphical test. BMJ 1997;315:629‐34.

Forneris CA, Nussbaumer B, Kaminski‐Hartenthaler A, Morgan LC, Gaynes BN, Sonis JH, et al. Psychological therapies for preventing seasonal affective disorder. Cochrane Database of Systematic Reviews 2014, Issue 9. [DOI: 10.1002/14651858.CD011270]

Gartlehner G, Nussbaumer B, Gaynes BN, Forneris CA, Morgan LC, Kaminski‐Hartenthaler A, et al. Second‐generation antidepressants for preventing seasonal affective disorder. Cochrane Database of Systematic Reviews 2014, Issue 9. [DOI: 10.1002/14651858.CD011268]

Golden RN, Gaynes BN, Ekstrom RD, Hamer RM, Jacobsen FM, Suppes T, et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta‐analysis of the evidence. American Journal of Psychiatry 2005;162(4):656‐62.

McMaster University and Evidence Prime Inc. GRADEpro Guideline Development Tool. McMaster University and Evidence Prime Inc, 2015.

Hamilton M. A rating scale for depression. Journal of Neurology, Neurosurgery and Psychiatry 1960;23:56‐62.

Hansen RA, Moore CG, Dusetzina SB, Leinwand BI, Gartlehner G, Gaynes B. Controlling for drug dose in systematic review and meta‐analysis: a case study of effect of antidepressant dose. Medical Decision Making 2009;29(1):91‐103.

Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. www.cochrane‐handbook.org.

Joffe RT, Moul DE, Lam RW, Levitt AJ, Teicher MH, Lebeque B, et al. Light visor treatment for seasonal affective disorder: a multicenter study. Psychiatry Research 1993;46(1):29‐39.

Kaminski‐Hartenthaler A, Nussbaumer B, Forneris CA, Morgan LC, Gaynes BN, Sonis JH, et al. Melatonin and agomelatine for preventing seasonal affective disorder. Cochrane Database of Systematic Reviews 2014, Issue 9. [DOI: 10.1002/14651858.CD011271]

Lam RW, Levitt AJ, eds. Canadian Consensus Guidelines for the Treatment of Seasonal Affective Disorder. Clinical & Academic Publishing, 1999.

Lam RW, Levitt AJ, Levitan RD, Enns MW, Morehouse R, Michalak EE, et al. The Can‐SAD study: a randomized controlled trial of the effectiveness of light therapy and fluoxetine in patients with winter seasonal affective disorder. American Journal of Psychiatry 2006;163(5):805‐12.

Leon AC, Solomon DA, Mueller TI, Turvey CL, Endicott J, Keller MB. The Range of Impaired Functioning Tool (LIFE‐RIFT): a brief measure of functional impairment. Psychological Medicine 1999;29(4):869‐78.

Levitan RD. What is the optimal implementation of bright light therapy for seasonal affective disorder (SAD)?. Journal of Psychiatry and Neuroscience 2005;30:72.

Levitan RD. The chronobiology and neurobiology of winter seasonal affective disorder. Dialogues in Clinical Neuroscience 2007;9(3):315‐24.

Lewy AJ, Sack RL, Miller LS, Hoban TM. Antidepressant and circadian phase‐shifting effects of light. Science 1987;235:352‐4.

Lewy AJ, Lefler BJ, Emens JS, Bauer VK. The circadian basis of winter depression. Proceedings of the National Academy of Sciences of the United States of America 2006;103:7414‐9.

Magnusson A, Partonen T. The diagnosis, symptomatology, and epidemiology of seasonal affective disorder. CNS Spectrums 2005;10(8):625‐34.

Pail G, Huf W, Pjrek E, Winkler D, Willeit M, Praschak‐Rieder N, et al. Bright‐light therapy in the treatment of mood disorders. Neuropsychobiology 2011;64:152‐62.

Partonen T, Lonnqvist J. Seasonal affective disorder. Lancet 1998;352:1369‐74.

Quera‐Salva MA, Hartley S, Barbot F, Alvarez JC, Lofaso F, Guilleminault C. Circadian rhythms, melatonin and depression. Current Pharmaceutical Design 2011;17:1459‐70.

The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.2. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2012.

Rodin I, Thompson C. Seasonal affective disorder. Advances in Psychiatric Treatment 1997;3:352‐9.

Rosen LN, Targum SD, Terman M, Bryant MJ, Hoffman H, Kasper SF. Prevalence of seasonal affective disorder at four latitudes. Psychiatry Research 1990;31:131‐44.

Rosenthal R. The "file‐drawer problem" and tolerance for null results. Psychological Bulletin 1979;86:638‐41.

Rosenthal NE, Sack DA, Gillin JC, Lewy AJ, Goodwin FK, Davenport Y, et al. Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy. Archives of General Psychiatry 1984;41(1):72‐80.

Rosenthal NE, Moul DE, Hellekson CJ, Oren DA, Frank A, Brainard GC, et al. A multicenter study of the light visor for seasonal affective disorder: no difference in efficacy found between two different intensities. Neuropsychopharmacology 1993;8(2):151‐60.

Schwartz PJ, Brown C, Wehr TA, Rosenthal NE. Winter seasonal affective disorder: a follow‐up study of the first 59 patients of the National Institute of Mental Health Seasonal Studies Program. American Journal of Psychiatry 1996;153(8):1028‐36.

Sohn CH, Lam RW. Update on the biology of seasonal affective disorder. CNS Spectrums 2005;10(8):635‐46.

Teicher MH, Gold CA, Oren DA, Schwartz PJ, Luetke C, Brown C, Rosenthal NE. The phototherapy light visor: more to it than meets the eye. American Journal of Psychiatry 1995;152(8):1197‐202.

Terman M, Terman JS. Light therapy for seasonal and nonseasonal depression: efficacy, protocol, safety, and side effects. CNS Spectrums 2005;10:647‐63.

Thaler K, Delivuk M, Chapman A, Gaynes BN, Kaminski A, Gartlehner G. Second‐generation antidepressants for seasonal affective disorder. Cochrane Database of Systematic Reviews 2011, Issue 12. [DOI: 10.1002/14651858.CD008591.pub2]

Ware JE, Sherbourne CD. The MOS 36‐item short‐form health survey (SF‐36). I. Conceptual framework and item selection. Medical Care 1992;30(6):473‐83.

Wells GA, Shea B, Peterson J, Welch V, Losos M, Tugwell P. The Newcastle Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta‐analyses. Ottawa: Canadian Agency for Drugs and Technologies in Health (http://www.ohri.ca/programs/clinical_epidemiology/oxford.htm)2009.

Google Scholar

Westrin A, Lam RW. Long‐term and preventative treatment for seasonal affective disorder. CNS Drugs 2007;21(11):901‐9.

Williams JBW, Link MJ, Rosenthal NE, Terman M. Structured Interview Guide for the Hamilton Depression Rating Scale ‐ Seasonal Affective Disorder version (SIGH‐SAD). New York: New York State Psychiatric Institute, 2012.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

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estudios excluidos

Meesters 1999

Methods	Single‐centre, non‐blinded, randomised controlled trial (duration: 2 winter seasons 1993‐94 and 1994‐95, October‐April each season) conducted in the Netherlands. 8 dropouts (4 bright white visor light, 3 infrared visor light, 1 no light exposure)
Participants	46 adult outpatients with a history of SAD who were without symptoms at the beginning of the study and were free of drugs Bright white visor light group: n = 18, but participant characteristics of only 14 participants reported: 2 men, mean age 41 years (± 12.7), 12 women, mean age 39.5 years (± 9.3) Infrared visor light group: n = 18, but participant characteristics of only 15 participants reported: 5 men, mean age 35.4 years (± 6.9), 10 women, mean age 36.6 years (± 4.9) No light exposure group: n = 10, but participant characteristics of only 9 participants reported: 4 men, mean age 47.5 years (± 7), 5 women, mean age 39.4 years (± 8) No information about number of prior depressive episodes nor other participant characteristics
Interventions	Bright white visor light (n = 18; 30 minutes/d in the morning except on weekends) vs infrared visor light (n = 18; 30 minutes/d in the morning except on weekends) vs no light exposure (n = 10) from October until April
Outcomes	Development of depression (BDI ≥ 13, SIGH‐SAD‐SR ≥ 20), development of severe depression (BDI ≥ 22, SIGH‐SAD‐SR ≥ 40)
Notes	Study was not funded by pharmaceutical industry; however, equipment was sponsored by Bio Bright, Inc. Study was identified by searches of electronic databases
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information about generation of random sequence provided
Allocation concealment (selection bias)	Unclear risk	No information about allocation concealment provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not blinded to treatment
Blinding of outcome assessment (detection bias) All outcomes	High risk	We assume that the outcome assessment was performed by the participants themselves: "patients stopped participating because of reasons unrelated to their illness, such as a lack of motivation to keep scoring self‐rating scales when in a healthy condition"
Incomplete outcome data (attrition bias) All outcomes	High risk	17% of dropouts were not taken into account in the data analysis. No participant characteristics (e.g. age, sex) were reported for these 8 dropouts
Selective reporting (reporting bias)	Unclear risk	We could not identify a protocol for this study. Therefore, we rated this domain unclear
Other bias	High risk	Intervention was implemented by participants on their own at their homes

BDI: Beck Depression Inventory.

SAD: Seasonal affective disorder.

SIGH‐SAD‐SR: Hamilton Depression Rating Scale‐Seasonal Affective Disorders self rating version.

Characteristics of excluded studies [ordered by study ID]

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estudios incluidos

Study	Reason for exclusion
Graw 1997	SAD participants were treated with light therapy when they suffered a depressive episode. They were interviewed again 2 to 5 years later. Treatment started when participants already had depressive symptoms ‐ not when they were free of symptoms; therefore, the study was not relevant for this systematic review
Kasper 1988	Study included participants without depressive symptoms, but also without a history of SAD. As the study investigated preventive effects of light therapy on healthy participants, it was not relevant for this systematic review
Kjellman 1997	Conference abstract
Lafer 1994	Study investigated treatment ‐ not prevention ‐ of SAD
Meesters 1991	Study investigated whether starting light therapy at an early stage of a depressive episode can prevent a full‐blown winter depressive episode. Included participants already had depressive symptoms when the study started; therefore, the study was not relevant for this systematic review
Meesters 1993	Study investigated whether starting light therapy at an early stage of a depressive episode can prevent a full‐blown winter depressive episode. Included participants already had depressive symptoms when the study started; therefore, the study was not relevant for this systematic review
Meesters 1994	Study included participants with a history of SAD and investigated preventive effects of light therapy. However, the study included only 1 intervention group and no control group, therefore, the study was not relevant for this systematic review
Meesters 1995	Study investigated treatment ‐ not prevention ‐ of SAD
Most 2010	Study investigated prevention of depression and sleep disturbances in the elderly with light. Included participants in this study were diagnosed with major depressive disorder without a seasonal pattern. Therefore, the study was not relevant for this systematic review
Norden 2000	Study investigated dawn simulation in participants with subsyndromal winter depression. Participants had no history of SAD
Partonen 1995	Study investigated recurrence ‐ not prevention ‐ of SAD. Included participants already had symptoms when the study started
Partonen 1996	Study included participants with a history of SAD and investigated preventive effects of light therapy. However, the study included only 1 intervention group and no control group; therefore, the study was not relevant for this systematic review
Rohan 2004	Study investigated acute and long‐term efficacy of cognitive‐behavioural therapy for SAD alone and in combination with light therapy as compared with solo light therapy. Included participants already had symptoms when interventions were started; therefore, the study was not relevant for this systematic review
Rohan 2007	Study investigated acute cognitive‐behavioural therapy for SAD alone and in combination with light therapy as compared with solo light therapy. This was a treatment study ‐ not a prevention study
Rohan 2009	Study investigated recurrence of SAD after 1 year of cognitive‐behavioural therapy, light therapy and a combination of these. Included participants already had depressive symptoms when the study started; therefore, it was not relevant for this systematic review
Rohan 2013	Study investigated relapse prevention of SAD and compared cognitive‐behavioural therapy, light therapy and a combination of these ‐ not prevention of SAD. Included participants already had symptoms when the study started
Terman 1994	Study investigated whether starting light therapy at an early stage of a depressive episode can prevent a full‐blown winter depressive episode. Included participants already had depressive symptoms when the study started, therefore, the study was not relevant for this systematic review
Thorell 1999	Study investigated relapse prevention ‐ not prevention of SAD. Included participants already had symptoms when the study started
University 2014	Study investigated relapse prevention of SAD and compared cognitive‐behavioural therapy, light therapy and a combination of these ‐ not prevention of SAD. Included participants already had symptoms when the study started
WELL 100006	Study investigated preventive effects of bupropion XL in participants with a history of SAD. It is included in the systematic review on efficacy and safety of second‐generation antidepressants; however, as it does not investigate efficacy nor safety of light therapy as preventive treatment, it is not relevant for this systematic review
WELL AK130936	Study investigated preventive effects of bupropion XL in participants with a history of SAD. It is included in the systematic review on efficacy and safety of second‐generation antidepressants; however, as it does not investigate efficacy nor safety of light therapy as preventive treatment, it is not relevant for this systematic review
WELL AKA130930	Study investigated preventive effects of bupropion XL in participants with a history of SAD. It is included in the systematic review on efficacy and safety of second‐generation antidepressants; however, as it does not investigate efficacy nor safety of light therapy as preventive treatment, it is not relevant for this systematic review
Wirz‐Justice 1990	Study investigated treatment ‐ not prevention ‐ of SAD. Included participants already had symptoms when the study started

SAD: Seasonal affective disorder.

Data and analyses

Open in table viewer

Comparison 1. Bright light therapy vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.1 Comparison 1 Bright light therapy vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).
2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.2 Comparison 1 Bright light therapy vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).
3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.3 Comparison 1 Bright light therapy vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).
4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.4 Comparison 1 Bright light therapy vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).
5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.5 Comparison 1 Bright light therapy vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).
6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.6 Comparison 1 Bright light therapy vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).
7 Overall rate of discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.7 Comparison 1 Bright light therapy vs no light therapy, Outcome 7 Overall rate of discontinuation.

Open in table viewer

Comparison 2. Infrared light therapy vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.1 Comparison 2 Infrared light therapy vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).
2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.2 Comparison 2 Infrared light therapy vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).
3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.3 Comparison 2 Infrared light therapy vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).
4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.4 Comparison 2 Infrared light therapy vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).
5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.5 Comparison 2 Infrared light therapy vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).
6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.6 Comparison 2 Infrared light therapy vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).
7 Overall rate of discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 2.7 Comparison 2 Infrared light therapy vs no light therapy, Outcome 7 Overall rate of discontinuation.

Open in table viewer

Comparison 3. Light therapy (bright white and infrared) vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.1 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).
2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.2 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).
3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.3 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).
4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.4 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).
5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.5 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).
6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.6 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).
7 Overall discontinuation Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 3.7 Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 7 Overall discontinuation.

Open in table viewer

Comparison 4. Bright light therapy vs infrared light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.1 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 1 Incidence of SAD (per protocol).
2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.2 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).
3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.3 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).
4 Incidence of severe SAD (per protocol) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.4 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 4 Incidence of severe SAD (per protocol).
5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.5 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).
6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.6 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).
7 Overall discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
Open in figure viewer Analysis 4.7 Comparison 4 Bright light therapy vs infrared light therapy, Outcome 7 Overall discontinuation.

Figure 1

PRISMA flow diagram.

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Figure 2

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across included studies.

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Figure 3

Risk of bias summary: review authors' judgements about each risk of bias item for the included study.

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Analysis 1.1

Comparison 1 Bright light therapy vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).

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Analysis 1.2

Comparison 1 Bright light therapy vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).

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Analysis 1.3

Comparison 1 Bright light therapy vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).

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Analysis 1.4

Comparison 1 Bright light therapy vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).

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Analysis 1.5

Comparison 1 Bright light therapy vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).

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Analysis 1.6

Comparison 1 Bright light therapy vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).

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Analysis 1.7

Comparison 1 Bright light therapy vs no light therapy, Outcome 7 Overall rate of discontinuation.

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Analysis 2.1

Comparison 2 Infrared light therapy vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).

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Analysis 2.2

Comparison 2 Infrared light therapy vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).

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Analysis 2.3

Comparison 2 Infrared light therapy vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).

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Analysis 2.4

Comparison 2 Infrared light therapy vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).

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Analysis 2.5

Comparison 2 Infrared light therapy vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).

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Analysis 2.6

Comparison 2 Infrared light therapy vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).

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Analysis 2.7

Comparison 2 Infrared light therapy vs no light therapy, Outcome 7 Overall rate of discontinuation.

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Analysis 3.1

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 1 Incidence of SAD (per protocol analysis).

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Analysis 3.2

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).

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Analysis 3.3

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).

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Analysis 3.4

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 4 Incidence of severe SAD (per protocol analysis).

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Analysis 3.5

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).

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Analysis 3.6

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).

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Analysis 3.7

Comparison 3 Light therapy (bright white and infrared) vs no light therapy, Outcome 7 Overall discontinuation.

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Analysis 4.1

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 1 Incidence of SAD (per protocol).

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Analysis 4.2

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 2 Incidence of SAD (ITT, assuming no dropout was depressed).

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Analysis 4.3

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 3 Incidence of SAD (ITT, assuming all dropouts were depressed).

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Analysis 4.4

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 4 Incidence of severe SAD (per protocol).

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Analysis 4.5

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 5 Incidence of severe SAD (ITT, assuming no dropout was depressed).

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Analysis 4.6

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 6 Incidence of severe SAD (ITT, assuming all dropouts were depressed).

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Analysis 4.7

Comparison 4 Bright light therapy vs infrared light therapy, Outcome 7 Overall discontinuation.

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Summary of findings for the main comparison. Bright white light therapy compared with no light therapy for prevention of SAD

Bright white light therapy compared with no light therapy for prevention of SAD
Patient or population: All participants were known SAD patients who had been successfully treated with conventional light therapy in previous winters Settings: This was an outpatient field study. Participants chose when (between 6 am and 9 am) and where they would use the visors Intervention: bright white light therapy Comparison: no light therapy
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect (95% CI)	Number of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	No light therapy	Light therapy
Incidence of SAD (SIGH‐SAD score ≥ 20) (follow‐up 26 weeks)	Low		RR 0.64 (0.30 to 1.38)	23 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	300 per 1000	192 per 1000 (90 to 414)
	Moderate
	500 per 1000	320 per 1000 (150 to 690)
	High
	600 per 1000	276 per 1000 (210 to 966)
Incidence of severe SAD (SIGH‐SAD‐SR (≥ 40)) (follow‐up 26 weeks)	Study population		RR 0.21 (0.03 to 1.75)	23 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	333 per 1000	70 per 1000 (10 to 583)
Overall discontinuation (follow‐up 26 weeks)	Study population		RR 2.22 (0.29 to 17.27)	28 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	100 per 1000	222 per 1000 (29 to 1000)
The basis for the assumed risk* (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: Confidence interval; RCT: Randomised controlled trial; RR: Risk ratio; SIGH‐SAD‐SR: Structured Interview Guide for the Hamilton Depression Rating Scale‐Seasonal Affective Disorders self rating version
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: We are very uncertain about the estimate
^aDowngraded 2 steps because of severe risk of bias due to non‐blinding and unclear randomisation process and allocation concealment; no intention‐to‐treat analysis was reported, outcomes were self rated, compliance throughout study duration was not checked and participant characteristics were not reported comprehensively ^bDowngraded 1 step because of small sample size (lack of power and random error could have influenced results)

Summary of findings for the main comparison. Bright white light therapy compared with no light therapy for prevention of SAD

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Summary of findings 2. Infrared light therapy compared with no light therapy for prevention of SAD

Infrared light therapy compared with no light therapy for prevention of SAD
Patient or population: All participants were known SAD patients who had been successfully treated with conventional light therapy in previous winters Settings: outpatient field study; participants chose when (between 6 am and 9 am) and where they would use the visors Intervention: infrared light therapy Comparison: no light therapy
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect (95% CI)	Number of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	No light therapy	Infrared light therapy
Incidence of SAD (SIGH‐SAD score ≥ 20) (follow‐up 26 weeks)	Low		RR 0.50 (0.21 to 1.17)	24 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	300 per 1000	150 per 1000 (63 to 351)
	Moderate
	500 per 1000	250 per 1000 (105 to 585)
	High
	600 per 1000	300 per 1000 (126 to 702)
Incidence of severe SAD (SIGH‐SAD‐SR (≥ 40)) (follow‐up 26 weeks)	Study population		RR 0.20 (0.20 to 1.64)	24 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	333 per 1000	67 per 1000 (67 to 547)
Overall discontinuation (follow‐up 26 weeks)	Study population		RR 1.67 (0.20 to 13.98)	28 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	100 per 1000	167 per 1000 (20 to 1000)
The basis for the assumed risk* (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: Confidence interval;RCT: Randomised controlled trial; RR: Risk ratio; SIGH‐SAD‐SR: Structured Interview Guide for the Hamilton Depression Rating Scale‐Seasonal Affective Disorders self rating version
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: We are very uncertain about the estimate
^aDowngraded 2 steps because of severe risk of bias due to non‐blinding and unclear randomisation process and allocation concealment; no intention‐to‐treat analysis was reported, outcomes were self rated, compliance throughout study duration was not checked and participant characteristics were not reported comprehensively ^bDowngraded 1 step because of small sample size (lack of power and random error could have influenced results)

Summary of findings 2. Infrared light therapy compared with no light therapy for prevention of SAD

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Summary of findings 3. Light therapy compared with no light therapy for prevention of SAD

Light therapy (bright white or infrared) compared with no light therapy for prevention of SAD
Patient or population: All participants were known SAD patients who had been successfully treated with conventional light therapy in previous winters Settings: outpatient field study; participants chose when (between 6 am and 9 am) and where they would use the visors Intervention: light therapy Comparison: no light therapy
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect (95% CI)	Number of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	No light therapy	Infrared light therapy
Incidence of SAD (SIGH‐SAD score ≥ 20) (follow‐up 26 weeks)	Low		RR 0.57 (0.30 to 1.10)	38 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	300 per 1000	171per 1000 (90 to 330)
	Moderate
	500 per 1000	285 per 1000 (150 to 550)
	High
	600 per 1000	342 per 1000 (180 to 660)
Incidence of severe SAD (SIGH‐SAD‐SR (≥ 40)) (follow‐up 26 weeks)	Study population		RR 0.21 (0.04 to 1.05)	38 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	333 per 1000	70 per 1000 (13 to 350)
Overall discontinuation (follow‐up 26 weeks)	Study population		RR 1.94 (0.27 to 14.01)	46 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	100 per 1000	194 per 1000 (27 to 1000)
The basis for the assumed risk* (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: Confidence interval;RCT: Randomised controlled trial; RR: Risk ratio; SIGH‐SAD‐SR: Structured Interview Guide for the Hamilton Depression Rating Scale‐Seasonal Affective Disorders self rating version
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: We are very uncertain about the estimate
^aDowngraded 2 steps because of severe risk of bias due to non‐blinding and unclear randomisation process and allocation concealment; no intention‐to‐treat analysis was reported, outcomes were self rated, compliance throughout study duration was not checked and participant characteristics were not reported comprehensively ^bDowngraded 1 step because of small sample size (lack of power and random error could have influenced results)

Summary of findings 3. Light therapy compared with no light therapy for prevention of SAD

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Summary of findings 4. Bright white light therapy compared with infrared light therapy for prevention of SAD

Bright white light therapy compared with infrared light therapy for prevention of SAD
Patient or population: All participants were known SAD patients who had been successfully treated with conventional light therapy in previous winters Settings: outpatient field study; participants chose when (between 6 am and 9 am) and where they would use the visors Intervention: bright white light therapy Comparison: infrared light therapy
Outcomes	Risk in both groups		Relative effect (95% CI)	Number of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk in this treatment group	Risk in this treatment group
	Infrared light therapy	Bright white light therapy
Incidence of SAD (SIGH‐SAD score ≥ 20) (follow‐up 26 weeks)	Study population		RR 1.29 (0.50 to 3.28)	29 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	333 per 1000	357 per 1000
Incidence of severe SAD (SIGH‐SAD‐SR (≥ 40)) (follow‐up 26 weeks)	Study population		RR 1.07 (0.07 to 15.54)	29 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	67 per 1000	71 per 1000
Overall discontinuation (follow‐up 26 weeks)	Study population		RR 1.33 (0.35 to 5.13)	36 (1 RCT)	⊕⊝⊝⊝ Very low^a,b
	167 per 1000	222 per 1000
CI: Confidence interval; RCT: Randomised controlled trial; RR: Risk ratio, SIGH‐SAD‐SR: Structured Interview Guide for the Hamilton Depression Rating Scale‐Seasonal Affective Disorders self rating version
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: We are very uncertain about the estimate
^aDowngraded 2 steps because of severe risk of bias due to non‐blinding and unclear randomisation process and allocation concealment; no intention‐to‐treat analysis was reported, outcomes were self rated, compliance throughout study duration was not checked and participant characteristics were not reported comprehensively ^bDowngraded 1 step because of small sample size (lack of power and random error could have influenced results)

Summary of findings 4. Bright white light therapy compared with infrared light therapy for prevention of SAD

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Comparison 1. Bright light therapy vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

7 Overall rate of discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

Comparison 1. Bright light therapy vs no light therapy

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Comparison 2. Infrared light therapy vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

7 Overall rate of discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

Comparison 2. Infrared light therapy vs no light therapy

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Comparison 3. Light therapy (bright white and infrared) vs no light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

4 Incidence of severe SAD (per protocol analysis) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

7 Overall discontinuation Show forest plot	1		Risk Ratio (M‐H, Fixed, 95% CI)	Totals not selected

Comparison 3. Light therapy (bright white and infrared) vs no light therapy

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Comparison 4. Bright light therapy vs infrared light therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incidence of SAD (per protocol) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

2 Incidence of SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

3 Incidence of SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

4 Incidence of severe SAD (per protocol) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

5 Incidence of severe SAD (ITT, assuming no dropout was depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

6 Incidence of severe SAD (ITT, assuming all dropouts were depressed) Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

7 Overall discontinuation Show forest plot	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected

Comparison 4. Bright light therapy vs infrared light therapy

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Referencias

References to studies included in this review

Meesters 1999 {published data only}

References to studies excluded from this review

Graw 1997 {published data only}

Kasper 1988 {published data only}

Kjellman 1997 {published data only}

Lafer 1994 {published data only}

Meesters 1991 {published data only}

Meesters 1993 {published data only}

Meesters 1994 {published data only}

Meesters 1995 {published data only}

Most 2010 {published data only}

Norden 2000 {published data only}

Partonen 1995 {published data only}

Partonen 1996 {published data only}

Rohan 2004 {published data only}

Rohan 2007 {published data only}

Rohan 2009 {published data only}

Rohan 2013 {published data only}

Terman 1994 {published data only}

Thorell 1999 {published data only}

University 2014 {published data only}

WELL 100006 {published data only}

WELL AK130936 {published data only}

WELL AKA130930 {published data only}

Wirz‐Justice 1990 {published data only}

Additional references

APA 1980

APA 1987

APA 2000

APA 2013

Begg 1994

Berg 1997

Byrne 2008

Ciarleglio 2011

Egger 1997

Forneris 2014

Gartlehner 2014

Golden 2005

GRADEpro 2015 [Computer program]

Hamilton 1960

Hansen 2009

Higgins 2011

Joffe 1993

Kaminski‐Hartenthaler 2014

Lam 1999

Lam 2006

Leon 1999

Levitan 2005

Levitan 2007

Lewy 1987

Lewy 2006

Magnusson 2005

Pail 2011

Partonen 1998

Quera‐Salva 2011

RevMan 2012 [Computer program]

Rodin 1997

Rosen 1990

Rosenthal 1979

Rosenthal 1984

Rosenthal 1993

Schwartz 1996

Sohn 2005

Teicher 1995

Terman 2005

Thaler 2010

Ware 1992

Wells 2009

Westrin 2007

Williams 2002

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Characteristics of excluded studies [ordered by study ID]

Data and analyses

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